Insight into the binding of alpha-linolenic acid (ALA) on human serum albumin using spectroscopic and molecular dynamics (MD) studies

Abstract

Alpha-linolenic acid (ALA) is one of the necessary fatty acids for the human body. It is a precursor for synthesizing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The consumption of ALA as an anti-inflammatory factor plays a significant role in preventing cardiovascular diseases. The current study was investigated to evaluate the binding affinity and molecular interactions between human serum albumin (HSA) with ALA through spectroscopic and computational studies. In the existence of ALA, the absorbance of HSA is reduced, confirming the development of the HSA-ALA complex. The fluorescence spectroscopic data implied that the quenching mechanism for HSA-ALA interaction was static mode. The negative values of ΔH° and ΔS° indicated that hydrogen bonding and van der Waals are the predominant intermolecular forces in the complex between HSA and ALA. The binding of ALA induces changes in the structure of HSA, which were revealed by far-UV circular dichroism (CD). The reduction of root mean square deviation (RMSD) after binding to ALA proved the stability of the structure of HSA in the presence of ALA. The results of the esterase activity of HSA presented that ALA competitively binds with HSA. This study demonstrated the importance of ALA in medicine and emphasized its main pharmacological significance.